Low-cost method for selectively reducing switch loss

ABSTRACT

A method includes identifying a first output terminal of a radio frequency front end (RFFE) switch including a single pole input terminal and a number (N) of output terminals, the first output terminal selectively connected to a single RF band path. Each of the N output terminals is a component of a respective one of N throws of the RFFE switch, with N being greater than one. The N output terminals include the first output terminal corresponding to a first throw of the N throws and at least one additional output terminal not connected to any radio frequency (RF) band path. The at least one additional output terminal includes a second output terminal corresponding to a second throw of the N throws. The method includes forming a parallel connection between the single pole input terminal and the single RF band path. The parallel connection provides at least two parallel branches for routing RF signals being transceived between the single pole input terminal and the single RF band path.

RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.16/460,375, filed Jul. 2, 2019, the content of which is incorporatedherein by reference.

BACKGROUND 1. Technical Field

The present disclosure generally relates to electronic devicearchitecture for radio frequency communications, and more particularlyto low-cost methods for selectively reducing switch loss withinelectronic devices engaged in radio frequency communications.

2. Description of the Related Art

Mobile communication devices are typically equipped with a printedcircuit board (PCB) that includes a radio frequency front end (RFFE)that transmits and receives radio frequency (RF) signals via one or moreantenna(s). Different geographical regions require wirelesscommunication systems to use different RF bands for cellularcommunication. For example, North America uses a subset of RF bands thatis different from the subset of RF bands used in South America, anddifferent from the subset of RF bands used in Asia. A smartphonemanufacturer will often release different variants of a single product(e.g., smartphone) so that each variant is configured to support adifferent subset of RF bands based on the different geographical regionsof the world where the product is sold to an end user (assuming regionaluse). The term “SKU” is commonly used to refer to a variant of a singleproduct, and means a given configuration of a product that ships to acertain region.

Current smartphone design practices entail designing a single-productPCB that is used worldwide, in every geographical region in which thesmartphone operates. That is, all variants of the single product havethe same identical PCB. The single-product PCB includes, within theRFFE, an antenna switch that can accommodate the full number of bandssupported across all SKUs. Components not required in a given SKU willnot be populated, which leaves unused switch throws. An unused switchthrow is an example of excess hardware.

Year after year, the number of RF bands required in smartphonescontinues to increase. In order to accommodate the multitude of RF bandsrequired in smartphones, the RFFE includes a high throw-count switchthat is placed near the antenna. The insertion loss of this highthrow-count switch has a positive correlation with the number of RFbands supported by the single-product PCB. This high throw-count switchis used as the antenna switch of the single-product PCB.

BRIEF DESCRIPTION OF THE DRAWINGS

The description of the illustrative embodiments is to be read inconjunction with the accompanying drawings. It will be appreciated thatfor simplicity and clarity of illustration, elements illustrated in thefigures have not necessarily been drawn to scale. For example, thedimensions of some of the elements are exaggerated relative to otherelements. Embodiments incorporating teachings of the present disclosureare shown and described with respect to the figures presented herein, inwhich:

FIG. 1 is a block diagram representation of an example mobile devicewithin which certain aspects of the disclosure can be practiced, inaccordance with one or more embodiments of this disclosure;

FIG. 2 illustrates a single product printed circuit board (PCB) that ispopulated with components required for worldwide geographical regionsand that includes a full-band antenna switch, in accordance with one ormore embodiments of this disclosure;

FIGS. 3A and 3B illustrate two examples of the single-product PCB ofFIG. 2 that is configured to include only components required to supportRF bands for a particular geographical region and that has been modifiedaccording to the low-cost methods for selectively reducing switch loss,in accordance with one or more embodiments of this disclosure; and

FIG. 4 is a flow chart illustrating low-cost methods for configuring anantenna switch and selectively reducing switch loss, in accordance withone or more embodiments.

DETAILED DESCRIPTION

Disclosed are a radio frequency front end (RFFE) switch configured forselectively reducing switch loss, a communication device with theconfigured RFFE switch, and a method for configuring the RFFE switch.The method includes providing the RFFE switch including a single poleinput terminal and a number (N) of output terminals. Each of the Noutput terminals is a component of a respective one of N throws of theRFFE switch, with N being greater than one. The N output terminalsinclude a first output terminal corresponding to a first throw of the Nthrows and at least one additional output terminal not connected to anyradio frequency (RF) band path. The at least one additional outputterminal includes a second output terminal corresponding to a secondthrow of the N throws. The method includes connecting the first outputterminal to a single RF band path. The method includes forming aparallel connection between the single pole input terminal and thesingle RF band path. The parallel connection provides at least twoparallel branches for routing RF signals being transceived between thesingle pole input terminal and the single RF band path. According to oneaspect of the method, forming the parallel connection includes, placinga jumper that connects the first output terminal to at least the secondoutput terminal, and closing the first throw and the second throw.

According to another embodiment, an RFFE switch includes a single poleinput terminal. The RFFE switch includes a number (N) of outputterminals. Each of the N output terminals is a component of a respectiveone of N throws of the RFFE switch, where N is greater than one. The Noutput terminals include a first output terminal corresponding to afirst throw of the N throws that connects to a single radio frequency(RF) band path, and at least one additional output terminal notconnected to any RF band path. The at least one additional outputterminal includes a second output terminal corresponding to a secondthrow of the N throws. The RFFE switch includes a parallel connectionformed between the single pole input terminal and the single RF bandpath. The parallel connection provides at least two parallel branchesfor routing RF signals being transceived between the single pole inputterminal and the single RF band path.

According to another embodiment, a communication device includes aprinted circuit board (PCB) including a number (N) of radio frequency(RF) signal paths for transmitting and receiving RF signals withinrespective single RF bands. The communication device includes a radiofrequency front end (RFFE) switch positioned on and connected to thePCB. The RFFE switch includes a single pole input terminal. The RFFEswitch includes a number (N) of output terminals. Each of the N outputterminals is a component of a respective one of N throws of the RFFEswitch, wherein N is greater than one. The N output terminals include afirst output terminal corresponding to a first throw of the N throwsthat connects to a single radio frequency (RF) band path, and at leastone additional output terminal not connected to any RF band path. The atleast one additional output terminal includes a second output terminalcorresponding to a second throw of the N throws. The RFFE switchincludes a parallel connection formed between the single pole inputterminal and the single RF band path. The parallel connection providesat least two parallel branches for routing RF signals being transceivedbetween the single pole input terminal and the single RF band path.

As a technical advantage, by utilizing a throw(s) of the RFFE switchthat corresponds to a depopulated RF band path(s), embodiments of thepresent disclosure overcome a problem of increased insertion lossresulting from increased quantity of RF bands supported by thesingle-product PCB, and the embodiments both reduce insertion loss andrepurpose excess hardware.

In the following description, specific example embodiments in which thedisclosure may be practiced are described in sufficient detail to enablethose skilled in the art to practice the disclosed embodiments. Forexample, specific details such as specific method sequences, structures,elements, and connections have been presented herein. However, it is tobe understood that the specific details presented need not be utilizedto practice embodiments of the present disclosure. It is also to beunderstood that other embodiments may be utilized and that logical,architectural, programmatic, mechanical, electrical and other changesmay be made without departing from general scope of the disclosure. Thefollowing detailed description is, therefore, not to be taken in alimiting sense, and the scope of the present disclosure is defined bythe appended claims and equivalents thereof.

References within the specification to “one embodiment,” “anembodiment,” “embodiments”, or “alternate embodiments” are intended toindicate that a particular feature, structure, or characteristicdescribed in connection with the embodiment is included in at least oneembodiment of the present disclosure. The appearance of such phrases invarious places within the specification are not necessarily allreferring to the same embodiment, nor are separate or alternativeembodiments mutually exclusive of other embodiments. Further, variousfeatures are described which may be exhibited by some embodiments andnot by others. Similarly, various aspects are described which may beaspects for some embodiments but not other embodiments.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a”, “an”, and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof. Moreover, the use of the terms first,second, etc. do not denote any order or importance, but rather the termsfirst, second, etc. are used to distinguish one element from another.

It is understood that the use of specific component, device and/orparameter names and/or corresponding acronyms thereof, such as those ofthe executing utility, logic, and/or firmware described herein, are forexample only and not meant to imply any limitations on the describedembodiments. The embodiments may thus be described with differentnomenclature and/or terminology utilized to describe the components,devices, parameters, methods and/or functions herein, withoutlimitation. References to any specific protocol or proprietary name indescribing one or more elements, features or concepts of the embodimentsare provided solely as examples of one implementation, and suchreferences do not limit the extension of the claimed embodiments toembodiments in which different element, feature, protocol, or conceptnames are utilized. Thus, each term utilized herein is to be providedits broadest interpretation given the context in which that term isutilized.

Those of ordinary skill in the art will appreciate that the hardwarecomponents and basic configuration depicted in the following figures mayvary. For example, the illustrative components within the presenteddevices are not intended to be exhaustive, but rather are representativeto highlight components that can be utilized to implement the presentdisclosure. For example, other devices/components may be used inaddition to, or in place of, the hardware depicted. The depicted exampleis not meant to imply architectural or other limitations with respect tothe presently described embodiments and/or the general disclosure.

Within the descriptions of the different views of the figures, the useof the same reference numerals and/or symbols in different drawingsindicates similar or identical items, and similar elements can beprovided similar names and reference numerals throughout the figure(s).The specific identifiers/names and reference numerals assigned to theelements are provided solely to aid in the description and are not meantto imply any limitations (structural or functional or otherwise) on thedescribed embodiments.

FIG. 1 illustrates a block diagram representation of a mobile device100, within which one or more of the described features of the variousembodiments of the disclosure can be implemented. Mobile device 100 maybe a handheld device a notebook computer, a mobile phone, a digitalcamera, a tablet computer, or any other suitable device, and may vary insize, shape, performance, functionality, and price.

Example mobile device 100 includes at least one processor integratedcircuit (IC), processor IC 105. Included within processor IC 205 aredata processor 107 and digital signal processor (DSP) 109. Processor IC205 is coupled to system memory 110 and non-volatile storage 220 via anintersystem communication fabric, such as system interconnect 115.System interconnect 115 can be interchangeably referred to as a systembus, in one or more embodiments. Also coupled to system interconnect 115is storage 120 within which can be stored one or more software and/orfirmware modules and/or data (not specifically shown).

As shown, system memory 110 can include therein a plurality of softwareand/or firmware modules including application(s) 112, operating system(O/S) 114, basic input/output system/unified extensible firmwareinterface (BIOS/UEFI) 116, and other firmware (F/W) 118. System memory120 may be a combination of volatile and non-volatile memory, such asrandom access memory (RAM) and read-only memory (ROM). That is, systemmemory 110 can store program code or similar data associated withapplications 112, O/S 114, BIOS/UEFI 116, and firmware 118. The softwareand/or firmware modules provide varying functionality when theircorresponding program code is executed by processor IC 205 or bysecondary processing devices within mobile device 100.

In some embodiments, storage 120 can be a hard drive or a solid-statedrive. The one or more software and/or firmware modules within storage120 can be loaded into system memory 110 during operation of DPS 100.The various software and/or firmware modules have varying functionalitywhen their corresponding program code is executed by processor IC 105 orother processing devices within DPS 100.

Processor IC 105 supports connection by, and processing of signals from,one or more connected input devices such as microphone 142, touch sensor144, camera 145, and keypad 146. Processor IC 105 also supportsconnection by and processing of signals to one or more connected outputdevices, such as speaker 152 and display 154. Additionally, in one ormore embodiments, one or more device interfaces 160, such as an opticalreader, a universal serial bus (USB), a card reader, Personal ComputerMemory Card International Association (PCMIA) slot, and/or ahigh-definition multimedia interface (HDMI), can be associated withmobile device 100. In at least one embodiment, device interfaces 160 canbe utilized to enable data to be read from or stored to additionaldevices (not shown) for example a compact disk (CD), digital video disk(DVD), flash drive, or flash memory card. These devices can collectivelybe referred to as removable storage devices, and are examples ofnon-transitory computer readable storage media. Mobile device 100 alsocontains a power source such as a battery 162 that supplies power tomobile device 100.

Mobile device 100 further includes Bluetooth transceiver 124,accelerometer 156, global positioning system module (GPS MOD) 158, andgyroscope 157, all of which are communicatively coupled to processor IC105. Bluetooth transceiver 124 enables mobile device 100 and/orcomponents within mobile device 100 to communicate and/or interface withother devices, services, and components that are located external tomobile device 100. GPS MOD 158 enables mobile device 100 to communicateand/or interface with other devices, services, and components to sendand/or receive geographic position information. Gyroscope 157communicates the angular position of mobile device 100 using gravity tohelp determine orientation. Accelerometer 156 is utilized to measurenon-gravitational acceleration and enables processor IC 105 to determinevelocity and other measurements associated with the quantified physicalmovement of a user.

Mobile device 100 is presented as a wireless communication device. As awireless device, mobile device 100 can transmit data over wirelessnetwork 170. Mobile device 100 includes a single product printed circuitboard, PCB 200, that is described more particularly below with referenceto FIG. 2. PCB (200) includes transceiver 164. Transceiver 164 iscommunicatively coupled to processor IC 105 and to antenna 166.Transceiver 164 allows for wide-area or local wireless communication,via wireless signal 167, between mobile device 100 and evolved node B(eNodeB) 188, or other base station, which includes antenna 189. Mobiledevice 100 is capable of wide-area or local wireless communication withother mobile wireless devices or with eNodeB 188 as a part of a wirelesscommunication network. Mobile device 100 communicates with other mobilewireless devices by utilizing a communication path involving transceiver164, antenna 166, wireless signal 167, antenna 189, and eNodeB 188.Mobile device 100 additionally includes near field communicationtransceiver (NFC TRANS) 168 and wireless power transfer receiver (WPTRCVR) 169. In one embodiment, other devices within mobile device 100utilize antenna 166 to send and/or receive signals in the form of radiowaves. For example, GPS module 158 can be communicatively couple toantenna 166 to send/and receive location data.

By transmitting data over wireless network 170, mobile device 100communicates and/or interfaces, via the communication network, withother devices, services, and components that are located external(remote) to mobile device 100. These devices, services, and componentscan interface with mobile device 100 via an external network, such asexample network 170, using one or more communication protocols. Network170 can be a local area network, wide area network, personal areanetwork, signal communication network, and the like, and the connectionto and/or between network 170 mobile device 100 can be wired or wirelessor a combination thereof. For purposes of discussion, network 170 isindicated as a single collective component for simplicity. However, itis appreciated that network 170 can comprise one or more directconnections to other devices as well as a more complex set ofinterconnections as can exist within a wide area network, such as theInternet.

In the description of the following figures, reference is alsooccasionally made to specific components illustrated within thepreceding figures, utilizing the same reference numbers from the earlierfigures. With reference now to FIG. 2, there is illustrated examplesingle product PCB 200 that exists within mobile device 100.Technologies described in this disclosure with respect to PCB 200 may beapplied to various communications systems, for example, 2G/3G/4G/5Gcommunications systems, and a next generation communications system, forexample, a Global System for Mobile Communications (GSM) system, a CodeDivision Multiple Access (CDMA) system, a Time Division Multiple Access(TDMA) system, a Wideband Code Division Multiple Access (WCDMA) system,a Frequency Division Multiple Access (FDMA) system, an OrthogonalFrequency-Division Multiple Access (OFDMA) system, a single-carrier FDMA(SC-FDMA) system, a General Packet Radio Service (GPRS) system, a LongTerm Evolution (LTE) system, LTE-Advanced system, and othercommunications systems.

In LTE technology, duplex modes are classified into two types: FrequencyDivision Duplex (FDD) and Time Division Duplex (TDD). In the FDD mode,different frequencies are used in uplink and downlink channels, andframes of fixed time lengths are used for both uplink transmission anddownlink transmission. In the TDD mode, uplink transmission and downlinktransmission are performed in different timeslots, and usually share asame frequency. Compared with FDD, TDD has characteristics of highfrequency utilization and flexible uplink and downlink resourceconfiguration.

As shown in FIG. 2, the circuitry of mobile device 100 includes PCB 200and an antenna 202. Multiple components are positioned on and connectedto PCB 200, including components such as RFFE 204, transceiver 206, andmodem 208. Within example mobile device 100 (FIG. 1), RFFE 204 ispositioned near the antenna 202. PCB 200 includes a number (N) of singleRF signal paths for transmitting and receiving RF signals withinrespective single-carrier RF signal transmission/reception channels.

Antenna 202 enables modem 208 to transmit one or more RF signals througha radio channel and to receive one or more RF signals through a radiochannel.

RFFE 204 connects antenna 202 to a modem 208. RFFE 204 implements radiofrequency transmission and reception in the above-listed types ofcommunications systems, for example, in an LTE system in a case ofinter-band carrier aggregation (CA). In order for mobile device 100 toperform reception functions, RFFE 204 receives a radio signal from aradio channel, converts the radio signal into a baseband analog signal,and sends the baseband analog signal to the baseband processor withinmodem 208. In order for mobile device 100 to perform transmissionfunctions, RFFE 204 receives a baseband analog signal from the basebandprocessor, converts the baseband analog signal into a radio signal, andtransmits the radio signal to a radio channel. RFFE 204 includes RFFEswitch 210, a power amplifier 214, and band-pass filter 212 a-212 n.Each band-pass filter 212 a-212 n is linked to a respective one of thesingle RF band paths among the full number (N) of RF bands that iscollectively used in all of the various geographical regions of theworld (i.e., all SKUs).

RFFE switch 210 is sometimes referred to as a full-band antenna switch.More particularly, RFFE switch 210 supports the full number (N) of RFbands that the LTE Protocol has assigned worldwide. In the embodimentshown in FIG. 2, RFFE switch 210 is implemented as a single-polemulti-throw switch, commonly referred to as a single-pole N-throw (SPNT)switch. An SPNT switch includes a single pole input terminal 216 and Noutput terminals 218 a-218 n, in which each of the N output terminals218 a-218 n is a component of a respective one of N throws 220 a-220 nof the SPNT switch. The number N is greater than one, and as anon-limiting example, RFFE switch 210 shown in FIG. 2 includes six (6)throws 220 a-220 n (i.e., N=6). In at least one other embodiment, RFFEswitch 210 is implemented as multiple SPNT switches. RFFE switch 210selects which of the RF bands that antenna 202 uses to transmit orreceive signals.

Input terminal 216 is connected to antenna 202. Input terminal 216enables all of the N throws 220 a-220 n to be connected to antenna 202at the same time.

Each of the output terminals 218 a-218 n corresponds to a throw thatconnects the input terminal 216 to a corresponding band path from amongthe full number (N) of RF band paths (shown in FIG. 2 as Band Path 1through Band Path n). Each of the full number (N) of RF band pathsincludes one of the N output terminals 218 a-218 n being connected to arespective one of the N band-pass filters 212 a-212 n. First outputterminal 218 a corresponds to a first throw 220 a that connects to BandPath 1 of PCB 200. Second output terminal 218 b corresponds to a secondthrow 220 b that connects to Band Path 2 of PCB 200.

Each of band-pass filters 212 a-212 n corresponds to a specific one ofthe full number (N) of RF bands paths. According to one aspect, eachoutput terminal 218 a can be associated with one LTE single-carrierband. For example, first band-pass filter 212 a corresponds to a firstLTE single-carrier band, second band-pass filter 212 b corresponds to asecond LTE single-carrier band, and N^(th) band-pass filter 212 ncorresponds to an N^(th) LTE single-carrier band. First band-pass filter212 a only allows frequencies that are within the first LTEsingle-carrier band to pass through from power amplifier 214 to RFFEswitch 210 during transmission of RF signals. Similarly, first band-passfilter 212 a only allows frequencies that are within the first LTEsingle-carrier band to pass through from RFFE switch 210 to transceiver206 during reception of RF signals. Analogously, second band-pass filter212 b only allows frequencies that are within the second LTEsingle-carrier band to pass through, and blocks other frequencies thatare outside the second LTE single-carrier band.

Power amplifier 214 amplifies low power RF signals outputted fromtransceiver 206 to a higher power level that can be successfullytransmitted to (i.e., received by) a base station (e.g., eNodeB 188 ofFIG. 1). Power amplifier 214 supports the full number (N) of RF bands.That is, power amplifier 214 can receive low power RF signals fromtransceiver 206 and output higher power RF signals to the N band-passfilters 212 a-212 n.

Transceiver 206 performs frequency up-conversion of signals received atantenna 202 and performs frequency down-conversion of signals to betransmitted from antenna 202.

Modem 208 includes a baseband processor (not shown), which processesbaseband signals in radio communication. Modem 208 performs modulationand demodulation, enabling mobile device 100 to transmit and receivedata wirelessly via a radio channel.

Single-product PCB 200 can support various regional SKUs, each SKU beinga configuration that supports communications within a subset of RF bandsassociated with a certain geographical region of the world. For example,the single-product PCB 200 supports a full number of RF bands that iscollectively used in all of the various geographical regions of theworld; However, a first SKU only uses a first subset of RF bands, whilea second SKU only uses a second subset of RF bands. PCB 200 is designedto include an RFFE switch 210 that supports whichever geographicalregion that requires the most (i.e., highest quantity) of RF bands. PCB200 includes RFFE switch 210 that supports the most bands on any givenSKU, although some SKUs will not require all of those RF bands. So,within a given SKU, the single-product PCB 200 can be populated withonly the components required for a given geographical region.

The insertion loss of RFFE switch 210 is primarily a factor of theresistance of the switch implementation. That is, the resistance (i.e.,R_(throw), measured in ohms) between input terminal 216 and one of theoutput terminals 218 a-218 n represents the resistance across one of thethrows 220 a-220 n in the closed position. In the switch implementationshown in FIG. 2, each one of the throws 220 a-220 n represents arespective circuit branch emanating from the commonly shared inputterminal 216. The power of an RF signal that is lost between the twoterminals of one of the throws 220 a-220 n is a directly proportional tothe resistance (R_(throw)) across the throw.

During operation, such as a transmission over a single-carrier RF signaltransmission channel, RFFE switch 210 exhibits high insertion loss. Theinsertion loss of this high throw-count RFFE switch 210 directly impactsoutput power, receive sensitivity, and current consumption of mobiledevice 100 (FIG. 1). The transmission power level of RF signals outputby antenna 202 is decreased directly by insertion loss of RFFE switch210. The insertion loss exhibited by RFFE switch 210 increases in directproportion with increases in the full number of RF bands that PCB 200supports, and the insertion loss directly impacts the output power ofthe mobile device 100. That is, if the full number (N) of RF bandsincreases, then the number (N) of throws within RFFE switch 210increases, which, in turn, results in greater insertion loss.

With reference now to FIGS. 3A and 3B, there are illustrated twoexamples of the single-product PCB 200 of FIG. 2 that is configured toinclude only components required to support RF bands for a particulargeographical region and that has been modified according to the low-costmethods for selectively reducing switch loss, in accordance with one ormore embodiments of this disclosure. The configurations of PCB 200 inFIGS. 3A and 3B show techniques that enable PCB 200 to support a lowerinsertion loss on a RF band path that is used for communication in theSKU by taking advantage of the fact that certain SKUs do not use certainRF band paths. In FIG. 3A, PCB 200 is configured to include componentsrequired to support the first RF band and the third through N^(th) RFbands, but not second RF band. That is, FIG. 3A illustrates an exampleconfiguration of PCB 200 for a first SKU. In FIG. 3B, PCB 200 isconfigured to include components required to support the first RF band,third RF band, and N^(th) RF band, but not the second, fourth, and fifthRF bands. That is, FIG. 3B illustrates an example configuration of PCB200 for a second SKU. It is understood that the configurations of thefirst and second SKUs of FIGS. 3A and 3B can be applied in any wirelesscommunication system. As a particular example in an LTE Protocol system,in order to configure PCB 200 for placement within a North America SKUproduct, components required to support LTE band 41, band 7, and band 30would be populated on the PCB, but no components would be populated forband 40. In North America, LTE band 40 is not required for wirelesscommunication systems. As another example, in order to configure PCB 200for placement within a China SKU product, components required to supportLTE band 40, band 7, and band 41 would be populated on the PCB, but nocomponents would be populated for band 30. In China, LTE band 30 is notrequired for wireless communication systems. Single-product PCB designaccommodates all of the different geographical SKUs.

As shown in FIG. 3A, PCB 200 is modified for placement into a mobiledevice that is configured according to requirements of the first SKU. Asthe first SKU does not require communications over the second RF band,PCB 200 is modified by depopulating (e.g., removing) second band-passfilter 212 b. As a result of depopulating second band-pass filter 212 b,Band Path 2 is eliminated (illustrated by double strike-through styletext). That is, second throw 220 b (including second output terminal 218b) is not connected to any band-pass filter, and thus is not connectedto any RF band path.

PCB 200 is modified to form a parallel connection between input terminal216 and Band Path 1 at first output terminal 218 a. In forming theparallel connection, one end of jumper 302 is connected to first outputterminal 218 a, another end of jumper 302 is connected to second outputterminal 218 b, and first throw 220 a and send throw 220 b are closed.As an example, jumper 302 could be a zero (0) ohm resistor, a seriesresonant capacitor, a parallel resonant inductor, or any suitable shuntconnector. In at least one embodiment, first throw 220 a and send throw220 b are actuated at the same time to transition from an open positionto a closed position. In another embodiment, the first throw 220 a andsend throw 220 b may be actuated separately to commence transition fromthe open position to the closed position at different times, but toremain in the closed position concurrently. The parallel connectionprovides at least two parallel branches for routing RF signals beingtransmitted from or received at input terminal 216 and Band Path 1. Oneof the parallel branches includes input terminal 216 at one end, firstthrow 220 a in the closed position, and at the other end, both jumper302 and first output terminal 218 a. The other parallel branch includesinput terminal 216 at one end, second throw 220 b in the closedposition, and at the other end, both jumper 302 and second outputterminal 218 b.

The insertion loss of RFFE switch 210 is primarily a factor of theresistance of the switch implementation. In the switch implementationshown in FIGS. 3A and 3B, each one of the throws 220 a-220 n representsa respective circuit branch emanating from the commonly shared inputterminal 216, such that when a parallel connection is formed between twoof the throws 220 a and 220 b, the parallel connection (i.e., betweeninput terminal 216 and first output terminal 218 a) exhibits anequivalent resistance

$\left( {R_{EQ} = \frac{R_{throw}}{2}} \right)$

that is half of the resistance (R_(throw)) of one closed throw. Duringoperation, such as during a transmission over single-carrier RF signaltransmission channel associated with Band Path 1, RFFE switch 210 ofFIG. 3A, which is modified according to the low-cost methods forselectively reducing switch loss, exhibits a reduced insertion loss. Thereduced insertion loss is a result of the approximately 50% reduction inresistance.

As shown in FIG. 3B, PCB 200 is modified for placement into a mobiledevice that is configured according to requirements of the second SKU.As the second SKU does not require communications over the second,fourth, and fifth RF bands, PCB 200 is modified by depopulating secondband-pass filter 212 b, fourth band-pass filter 212 d, and fifthband-pass filter 212 e. Band Path 2, Band Path 4, and Band Path 5 areeliminated (illustrated by double strike-through style text) as a resultof depopulating the above listed three band-pass filters 212 b, 212 d,and 212 e. That is, second, fourth, and fifth throws 220 b, 220 d, and220 e are not connected to any band-pass filter, and thus are notconnected to any RF band path.

PCB 200 is modified to form a first parallel connection between inputterminal 216 and Band Path 1 at first output terminal 218 a, asdescribed above with reference to jumper 302 of FIG. 3A. Further, PCB200 is modified to form a second parallel connection between inputterminal 216 and Band Path n at N^(th) output terminal 218 n. The secondparallel connection can be formed in a variety of ways. According to oneembodiment, the second parallel connection is formed by: connecting oneend of a two-terminal jumper 304 b or 304 a (respectively) to N^(th)output terminal 218 n; connecting the other end of jumper 304 a to anadditional output terminal of RFFE switch 210 (i.e., fourth outputterminal 218 d or fifth output terminal 218 e, respectively) notconnected to any RF band path; closing N^(th) throw 220 n; and closingthe throw (i.e., fourth throw 220 d or fifth throw 220 e, respectively)corresponding to the additional output terminal of RFFE switch 210.According to another embodiment, the second parallel connection isformed by: connecting one terminal of a multi-terminal jumper 304 c(together 304 a and 304 b) to N^(th) output terminal 218 n; connectingother terminals of jumper 304 c to multiple additional output terminalsof RFFE switch 210 (i.e., fourth output terminal 218 d and fifth outputterminal 218 e); closing N^(th) throw 220 n; and closing the throws(i.e., fourth throw 220 d and fifth throw 220 e) corresponding to themultiple additional output terminals of RFFE switch 210. The secondparallel connection provides at least two parallel branches for routingRF signals being transmitted from or received at input terminal 216 andBand Path n. One of the parallel branches includes input terminal 216 atone end, N^(th) throw 220 n in the closed position, and at the otherend, both N^(th) output terminal 218 n and jumper 304 a, 304 b, or 304c. The second parallel branch includes input terminal 216 at one end,fifth throw 220 e in the closed position, and at the other end, bothfifth output terminal 218 e and jumper 304 a or 304 c. The thirdparallel branch includes input terminal 216 at one end, fourth throw 220d in the closed position, and at the other end, both fourth outputterminal 218 d and jumper 304 b or 304 c.

When the second parallel connection (i.e., between input terminal 216and N^(th) output terminal 218 n) includes three parallel branches, thesecond parallel connection exhibits an equivalent resistance

$\left( {R_{EQ} = \frac{R_{throw}}{3}} \right)$

that is one-third of the resistance (R_(throw)) of one closed throw.During a transmission over a single-carrier RF signal transmissionchannel, RFFE switch 210 of FIG. 3B, which is modified according to thelow-cost methods for selectively reducing switch loss, exhibits areduced insertion loss. The reduced insertion loss is a result of theapproximately 33⅓% reduction in resistance.

Carrier Aggregation (CA) technology is a key technology in LTE, and isused to implement aggregation of carriers at two frequencies. Generally,the CA technology may be implemented by using a radio frequency circuitof a mobile device. Three types of carrier aggregation modes includeintra-band contiguous CA, intra-band non-contiguous CA, and inter-bandCA. Usually, the inter-band CA is applicable to a scenario of widefrequency spacing. Since frequency resources vary across globalcommunications markets, the CA technology focuses on promoting thecapability of a radio frequency circuit to support wider frequencyspacing.

As shown in FIGS. 3A and 3B, the low-cost methods for selectivelyreducing switch loss can be combined with CA technology. For example, aninter-band CA type scenario can be used to transceive (i.e., transmitand receive) RF signals via Band Path 1 (associated with the firstparallel connection) and via Band Path n (associated with the secondparallel connection) with reduced insertion loss resulting from thelow-cost methods for selectively reducing switch loss according toembodiments of this disclosure.

With reference now to FIG. 4, there is illustrated an example method 400for configuring an antenna switch and selectively reducing switch loss,in accordance with one or more embodiments. For example, the method 400can be executed by manufacturing a PCB 200 (as shown in FIG. 2) andconfiguring it as shown in FIGS. 3A-3B. Method 400 begins at the startblock, then proceeds to block 402. At block 402, method 400 includesproviding an RFFE switch 210. For example, as shown in FIG. 2,single-product PCB 200 is provided, which includes RFFE switch 210 as acomponent. In at least one embodiment, RFFE switch 210 is provided, andthen populated onto a PCB in order to complete formation ofsingle-product PCB 200 of FIG. 2. At block 404, method 400 includesmodifying PCB 200 of FIG. 2 to include only components required tosupport RF bands for a particular geographical region or a particularSKU. More particularly, at block 404, method 400 includes depopulatingcomponents from PCB 200 of FIG. 2 that are not requirements for theparticular SKU. As shown in the example of FIG. 3A, PCB 200 is modifiedby depopulating (e.g., removing) second band-pass filter 212 b, giventhat the first SKU does not require communications over the second RFband. As shown in the example of FIG. 3B, PCB 200 is modified bydepopulating second band-pass filter 212 b, fourth band-pass filter 212d, and fifth band-pass filter 212 e, given that the second SKU does notrequire communications over the second, fourth, and fifth RF bands. Atblock 406, method 400 includes connecting a first output terminal to asingle-carrier RF band path. For example, as shown in FIG. 3B, firstoutput terminal 218 a is connected to Band Path 1 at first band-passfilter 212 a. At block 408, method 400 includes forming a parallelconnection between the input terminal and the single-carrier RF bandpath. For example, as shown in FIG. 3B, a first parallel connection isformed between input terminal 216 and Band Path 1 at first outputterminal 218 a.

In at least one embodiment, the parallel connection can be formed byplacing (at block 410) a jumper that connects the first output terminalto and an second additional output terminal, and by closing (at block412) first and second throws of the RFFE switch, which correspond to thefirst output terminal and additional output terminal, respectively. Forexample, as shown in FIG. 3B, the first parallel connection is formed byplacing jumper 302 between first output terminal 218 a and second outputterminal 218 b and by closing first throw 220 a and second throw 220 b.

At block 414, method 400 includes connecting a third output terminal ofthe RFFE switch to a second single-carrier RF band path. For example, asshown in FIG. 3B, N^(th) output terminal 218 n is connected to Band Pathn at N^(th) band-pass filter 212 n. At block 416, method 400 includesforming a second parallel connection between the input terminal and thesecond single-carrier RF band path. For example, as shown in FIG. 3B, asecond parallel connection is formed between input terminal 216 and BandPath n at N^(th) output terminal 218 n.

In at least one embodiment, the second parallel connection can be formedby placing (at block 418) a jumper that connects the third outputterminal to and an fourth additional output terminal, and by closing (atblock 420) third and fourth throws of the RFFE switch, which correspondto the third output terminal and fourth additional output terminal,respectively. For example, as shown in FIG. 3B, the second parallelconnection is formed by placing jumper 304 a between N^(th) outputterminal 218 n and fifth output terminal 218 e and by closing N^(th)throw 220 n and fifth throw 220 e. As another example, as shown in FIG.3B, the second parallel connection is formed by connecting threeterminals of jumper 304 c to N^(th) output terminal 218 n and both ofthe fourth and fifth additional output terminals 218 d and 218 e and byclosing N^(th) throw 220 n and both of the fourth and fifth throws 220 dand 220 e, which correspond to the additional output terminals 218 d and218 e, respectively. The method 400 concludes at the end block.

In the above-described flowchart of FIG. 4, one or more of the methodprocesses may be embodied in a computer readable device containingcomputer readable code such that a series of steps are performed whenthe computer readable code is executed on a computing device. In someimplementations, certain steps of the methods are combined, performedsimultaneously or in a different order, or perhaps omitted, withoutdeviating from the scope of the disclosure. Thus, while the method stepsare described and illustrated in a particular sequence, use of aspecific sequence of steps is not meant to imply any limitations on thedisclosure. Changes may be made with regards to the sequence of stepswithout departing from the spirit or scope of the present disclosure.Use of a particular sequence is therefore, not to be taken in a limitingsense, and the scope of the present disclosure is defined only by theappended claims.

Aspects of the present disclosure are described above with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems) and computer program products according to embodiments of thedisclosure. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer program instructions. Computer program code for carrying outoperations for aspects of the present disclosure may be written in anycombination of one or more programming languages, including anobject-oriented programming language, without limitation. These computerprogram instructions may be provided to a processor of a general purposecomputer, special purpose computer, or other programmable dataprocessing apparatus to produce a machine that performs the method forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. The methods are implemented when theinstructions are executed via the processor of the computer or otherprogrammable data processing apparatus.

As will be further appreciated, the processes in embodiments of thepresent disclosure may be implemented using any combination of software,firmware, or hardware. Accordingly, aspects of the present disclosuremay take the form of an entirely hardware embodiment or an embodimentcombining software (including firmware, resident software, micro-code,etc.) and hardware aspects that may all generally be referred to hereinas a “circuit,” “module,” or “system.” Furthermore, aspects of thepresent disclosure may take the form of a computer program productembodied in one or more computer readable storage device(s) havingcomputer readable program code embodied thereon. Any combination of oneor more computer readable storage device(s) may be utilized. Thecomputer readable storage device may be, for example, but not limitedto, an electronic, magnetic, optical, electromagnetic, infrared, orsemiconductor system, apparatus, or device, or any suitable combinationof the foregoing. More specific examples (a non-exhaustive list) of thecomputer readable storage device can include the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a portable compact disc read-only memory (CD-ROM), anoptical storage device, a magnetic storage device, or any suitablecombination of the foregoing. In the context of this document, acomputer readable storage device may be any tangible medium that cancontain, or store a program for use by or in connection with aninstruction execution system, apparatus, or device.

Where utilized herein, the terms “tangible” and “non-transitory” areintended to describe a computer-readable storage medium (or “memory”)excluding propagating electromagnetic signals; but are not intended tootherwise limit the type of physical computer-readable storage devicethat is encompassed by the phrase “computer-readable medium” or memory.For instance, the terms “non-transitory computer readable medium” or“tangible memory” are intended to encompass types of storage devicesthat do not necessarily store information permanently, including, forexample, RAM. Program instructions and data stored on a tangiblecomputer-accessible storage medium in non-transitory form may afterwardsbe transmitted by transmission media or signals such as electrical,electromagnetic, or digital signals, which may be conveyed via acommunication medium such as a network and/or a wireless link.

While the disclosure has been described with reference to exampleembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the disclosure. Inaddition, many modifications may be made to adapt a particular system,device, or component thereof to the teachings of the disclosure withoutdeparting from the scope thereof. Therefore, it is intended that thedisclosure not be limited to the particular embodiments disclosed forcarrying out this disclosure, but that the disclosure will include allembodiments falling within the scope of the appended claims.

The description of the present disclosure has been presented forpurposes of illustration and description, but is not intended to beexhaustive or limited to the disclosure in the form disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope of the disclosure. Thedescribed embodiments were chosen and described in order to best explainthe principles of the disclosure and the practical application, and toenable others of ordinary skill in the art to understand the disclosurefor various embodiments with various modifications as are suited to theparticular use contemplated.

1. A method comprising: identifying a first output terminal of a singleinput radio frequency front end (RFFE) switch that includes a singlepole input terminal and multiple output terminals, each of the multipleoutput terminals being corresponding to a respective one of multiplethrows of the RFFE switch, the multiple output terminals comprising thefirst output terminal corresponding to a first throw of the multiplethrows and at least one additional output terminal not connected to anyradio frequency (RF) band path; and forming a parallel connectionbetween the single pole input terminal and a single RF band path, theparallel connection providing at least two branches for routing RFsignals being transceived between the single pole input terminal and thesingle RF band path.
 2. The method of claim 1, wherein the RFEE switchis a single-pole N-throw switch and forming the parallel connectioncomprises: placing a jumper that connects the first output terminal toat least a second output terminal from among the at least one additionaloutput terminal, the second output terminal corresponding to a secondthrow of the multiple throws; and closing the first throw and the secondthrow.
 3. The method of claim 2, wherein: the at least one additionaloutput terminal comprises multiple additional output terminals and thejumper connects the first output terminal to multiple of the at leastone additional output terminal; and the method further comprises, foreach of the multiple additional output terminals to which the jumperconnects, configuring a corresponding throw to form a branch of theparallel connection when the corresponding throw is closed.
 4. Themethod of claim 2, wherein the jumper comprises at least one of a zero(0) ohm resistor, a series resonant capacitor, or a parallel resonantinductor.
 5. The method of claim 1, wherein: the single pole inputterminal is connected to an antenna to enable transmission and receptionof the RF signals via the antenna.
 6. The method of claim 1, wherein:the multiple output terminals of the RFFE switch further comprise athird output terminal corresponding to a third throw of the multiplethrows and selectively connected to a second single RF band path; the atleast one additional output terminal includes a fourth output terminalcorresponding to a fourth throw of the multiple throws; and the methodfurther comprises forming a parallel connection between the single poleinput terminal and the second single RF band path, the parallelconnection providing at least two parallel branches for routing RFsignals being transceived between the single pole input terminal and thesecond single RF band path.
 7. A radio frequency front end (RFFE) switchcomprising: a single pole input terminal; multiple output terminals,each output terminal being connectable to the single pole input terminalvia a respective one of multiple throws of the RFFE switch, the multipleoutput terminals comprising: a first output terminal corresponding to afirst throw that is selectively connected to a single RF band path; andat least one additional output terminal not connected to an RF bandpath, each of the at least one additional output terminal correspondingto a respective throw; and a parallel connection formed between thesingle pole input terminal and the single RF band path, the parallelconnection providing at least two parallel branches for routing RFsignals being transceived between the single pole input terminal and thesingle RF band path.
 8. The RFFE switch of claim 7, wherein the parallelconnection comprises: a closed configuration of the first throw and asecond throw corresponding to a second output terminal of the at leastone additional output terminals; and a jumper that connects the firstoutput terminal to at least the second output terminal.
 9. The RFFEswitch of claim 8, wherein: the at least one additional output terminalcomprises multiple additional output terminals; the jumper connects thefirst output terminal to multiple terminals from among the at least oneadditional output terminal; and each of the multiple additional outputterminals are a component of a respective throw that closes to form abranch of the parallel connection.
 10. The RFFE switch of claim 8,wherein the jumper comprises at least one of a zero (0) ohm resistor, aseries resonant capacitor, or a parallel resonant inductor.
 11. The RFFEswitch of claim 7, wherein the single pole input terminal is connectedto an antenna to enable transmission and reception of the RF signals viathe antenna.
 12. The RFFE switch of claim 7, wherein: the multipleoutput terminals further comprise a third output terminal correspondingto a third throw that connects to a second single RF band path; the atleast one additional output terminals includes a fourth output terminalcorresponding to a fourth throw of the multiple throws; and a parallelconnection is formed between the single pole input terminal and thesecond single RF band path, the parallel connection providing at leasttwo parallel branches for routing RF signals being transceived betweenthe single pole input terminal and the second single RF band path.
 13. Acommunication device comprising: a radio frequency front end (RFFE)switch comprising: a single pole input terminal; multiple outputterminals, each output terminal being connectable to the single poleinput terminal via a respective one of multiple throws of the RFFEswitch, the multiple output terminals comprising: a first outputterminal corresponding to a first throw that is selectively connected toa single RF band path on a printed circuit board (PCB); and at least oneadditional output terminal not connected to an RF band path on the PCB,each of the at least one additional output terminal corresponding to arespective throw; and a parallel connection formed between the singlepole input terminal and the single RF band path, the parallel connectionproviding at least two parallel branches for routing RF signals beingtransceived between the single pole input terminal and the single RFband path.
 14. The communication device of claim 13, wherein theparallel connection comprises: a closed configuration of the first throwand a second throw corresponding to a second output terminal of the atleast one additional output terminals; and a jumper that connects thefirst output terminal to at least the second output terminal.
 15. Thecommunication device of claim 14, wherein: the at least one additionaloutput terminal comprises multiple additional output terminals; thejumper connects the first output terminal to multiple output terminalsfrom among the at least one additional output terminal; and each of themultiple additional output terminals are a component of a respectivethrow that is closed to form a branch of the parallel connection. 16.The communication device of claim 14, wherein the jumper comprises atleast one of a zero (0) ohm resistor, a series resonant capacitor, or aparallel resonant inductor.
 17. The communication device of claim 13,wherein the single pole input terminal of the RFFE switch is configuredto connect to an antenna for transmission or reception of the RF signalsvia the antenna.
 18. The communication device of claim 13, wherein,within the RFFE switch: the multiple output terminals further comprise athird output terminal corresponding to a third throw that connects to asecond single RF band path; the at least one additional output terminalsincludes a fourth output terminal corresponding to a fourth throw of themultiple throws; and a parallel connection is formed between the singlepole input terminal and the second single RF band path, the parallelconnection providing at least two parallel branches for routing RFsignals being transceived between the single pole input terminal and thesecond single RF band path.